Item handling systems, such as mailpiece handling systems, for example, are known in the art. These systems include inserter systems, which create mailpieces and prepare them for mailing, as well as sorter systems, which sort completed mailpieces and direct the mailpieces to storage bins. Other types of item handling systems and related applications are known.
Inserter machines are used to create mailpieces for many different applications. Inserters contain a generally modular array of components to carry out the various processes associated with mailpiece creation. The processes include preparing documents, assembling the documents associated with a given mailpiece, adding any designated inserts, stuffing the assembly into an envelope, and printing information on the envelope.
Some inserter applications utilize ink jet printers to print the information, such as address information, advertisements, and/or a postal indicia, for example, on the face of the envelopes being processed. In those applications, which involve ink jet printing on a moving envelope, the alignment of the print heads may affect the image quality. Accordingly, it is desirable to calibrate the printers at certain intervals.
The calibration is presently accomplished by introducing a blank piece of paper (or a mailpiece) onto the vacuum belt transport that is in motion in the paper path direction. When the paper translates under the print heads, all four print heads print a test pattern on the paper. This test pattern consists of parallel lines in the paper path direction, printed by nozzles on each print head that are the same lateral distance from the edge of each respective print head and that have the same lateral spacing.
In conventional calibration methods, the printer is rotated such that sets of four printed lines, each generated by each pen, eventually fall directly on top of one another. However, to get all the lines to fall on top of one another is presently accomplished by a trial and error method. After the first test pattern is printed and a rotation adjustment is made, another test pattern is printed on another piece of paper followed by another rotation adjustment.
It is common to iterate this procedure ten or more times before the adjustment is declared close enough by one who is skilled with the procedure. This calibration procedure can take on the order of a half-hour to complete. The inefficiencies associated with the conventional procedure result in production mail down time, particularly when the procedure is carried out at frequent intervals, such as each time the print heads are replaced.